356 REPORT ON NATIONAL MUSEUM, 1886. 



Various solutions of beeswax, rosin, and coal tar have also been tried 

 with indifferent success. 



liansome's iiroccss. — This consists in saturating the stone as far as 

 practicable with a solution of silicate of soda or potash (waterglass) and 

 afterwards applying a solution of chloride of calcium. This last coming 

 in contact Avith the silicate produces by double decomposition an in- 

 soluble silicate of lime, cementing the grains of which the stone is 

 composed firmly together.* 



" The solution of silicate is first applied in a dilute form so as to be 

 absorbed readily into the pores of the stone. Several coats are applied 

 with an ordinary whitewash brush and when thoroughly dry the surface 

 is washed with rain water, again allowed to dry, and the calcium solu 

 tion applied in the same manner. The precautions to be used are : (I) 

 the stone must be clean and dry before applying the solution ; (2) the 

 silicate must be applied until the stone is fully saturated, but no excess 

 must be allowed to remain on the surface : (3) the calcium must not be 

 applied until after the silicate is dry ; a clear day or so should intervene 

 if possible ; (4) care must be taken that either solution is not splashed 

 upon the windows or upon painted work, as it can not be removed there- 

 from ; (5) upon no account should the same brush be used for both 

 solutions. Under ordinary circumstances about 4 gallons of each solu- 

 tion will be required for every 100 yards of surface." 



tSzerelmey's stone liquid is stated to be a combination of Kuhlman's 

 process with a temporary wash of some bituminous substance. The wall 

 being nmdc perfectly dry and clean, the licpiid is applied in two or three 

 coats with a painter's brush, until a slight glaze appears on the surface. 

 This composition was used with some success in arresting for a time 

 the decay of the stone in the House of Parliament. t 



Kuldmaii's irrovess consists in simply coating the surface of the stone 

 with a silicate of soda or potash solution. It is open to the objection 

 that the ])otash absorbs caibonic acid from the air and produces a dis- 

 agreeable elUorescence, which, however, disappears in time. 



M. Lcwins' process consists in coating the surface of the stone with 

 solutions of an alkaline silicate (silicate of potash) and alumina, the 

 latter in the form of sulphate. It is stated that this wash will give so 

 close a surface to sandstone that it can be polished.("?) Either of the 

 solutions can be colored if desired.| 



Very many other solutions have been devised and tried both in 

 Europe and in this country, but which, in the language of Professor 

 Julien, " have in most cases resulted in complete failure, not arresting 

 the exfoliation." 



* Dobson, Masoury and Stone-Cutting, p. 141. See also American Arch, and 

 Builder, 1877, :i, p. 21, 38, and Notes on Building Construction, p. 79. 

 tNotea on Building Construction, p 79. 

 \ Jour. Franklin Inst., 3rd, Ixix, 1875, p. 338. 



